The opposite of "false" is "true". And willful blindness as well as lack of due diligence or failure to investigate or failure to know what should have been known etc., are not legal excuses.
Moreover, I think it is flat out wrong to give others false comfort or, in any way or manner, encourage them to risk a defamation lawsuit. This is even more true for people who are emotionally caught up in a situation. Emotions are the root cause of many, many defamation lawsuits.
If you want to knowingly risk your own lawsuit, fine. But watch what you say to others. First, "do no harm" applies to more than doctors.